In XFCE4.10 (!) on the panel0 I put the Indicator Applet. It always showed me the volume control and network icons. When I updated to 13.10 and after cleaned some stuff, removed some orphaned package, I noticed, the volume control applet is showing mute and if I clicked on it there is an empty drowdown menu like 10x5 px.. Now it became completely useless. So my question is WHAT should I reinstall or change to get the control work?.. :/

Yes, I have this problem too. Unfortunately, it looks like this problem will not be fixed anytime soon even though it's marked of high importance. It's been around for 3 months and still hasn't been fixed yet :( Pretty sad given that sound control seems like a core feature.

There are workarounds on the bug report page, but I'm just going to wait for the fix.